587 research outputs found

    Biochar from Pyrolysis of Biosolids for Nutrient Adsorption and Turfgrass Cultivation

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    At water resource recovery facilities, nutrient removal is often required and energy recovery is an ever-increasing goal. Pyrolysis may be a sustainable process for handling wastewater biosolids because energy can be recovered in the py-gas and py-oil. Additionally, the biochar produced has value as a soil conditioner. The objective of this work was to determine if biochar could be used to adsorb ammonia from biosolids filtrate and subsequently be applied as a soil conditioner to improve grass growth. The maximum carrying capacity of base modified biochar for NH3−N was 5.3 mg/g. Biochar containing adsorbed ammonium and potassium was applied to laboratory planters simulating golf course putting greens to cultivate Kentucky bluegrass. Planters that contained nutrient-laden biochar proliferated at a statistically higher rate than planters that contained biosolids, unmodified biochar, peat, or no additive. Nutrient-laden biochar performed as well as commercial inorganic fertilizer with no statistical difference in growth rates. Biochar from digested biosolids successfully immobilized NH3−N from wastewater and served as a beneficial soil amendment. This process offers a means to recover and recycle nutrients from water resource recovery facilities

    Ammonia emissions from cattle urine and dung excreted on pasture

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    Twelve cattle were kept for three days in a circular area of 16 m radius on short pasture and fed with freshly-cut pasture. Ammonia (NH<sub>3</sub>) emissions from the urine and dung excreted by the cattle were measured with a micrometeorological mass-balance method, during the cattle presence and for 10 subsequent days. Daily-integrated emission rates peaked on Day 3 of the experiment (last day of cattle presence) and declined steadily for five days thereafter. Urine patches were the dominant sources for these emissions. On Day 9, a secondary emissions peak occurred, with dung pats likely to be the main sources. This interpretation is based on simultaneous observations of the pH evolution in urine patches and dung pats created next to the circular plot. Feed and dung samples were analysed to estimate the amounts of nitrogen (N) ingested and excreted. Total N volatilised as NH<sub>3</sub> was 19.8 (± 0.9)% of N intake and 22.4 (± 1.3)% of N excreted. The bimodal shape of the emissions time series allowed to infer separate estimates for volatilisation from urine and dung, respectively, with the result that urine accounted for 88.6 (± 2.6)% of the total NH<sub>3</sub> emissions. The emissions from urine represented 25.5 (± 2.0)% of the excreted urine-N, while the emissions from dung amounted to 11.6 (± 2.7)% of the deposited dung-N. Emissions from dung may have continued after Day 13 but were not resolved by the measurement technique. A simple resistance model shows that the magnitude of the emissions from dung is controlled by the resistance of the dung crust

    Ammonia emissions from cattle urine and dung excreted on pasture

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    Twelve cattle were kept for three days in a circular area of 16 m radius on short pasture and fed with freshly-cut pasture. Ammonia (NH₃) emissions from the urine and dung excreted by the cattle were measured with a micrometeorological mass-balance method, during the cattle presence and for 10 subsequent days. Daily-integrated emission rates peaked on Day 3 of the experiment (last day of cattle presence) and declined steadily for five days thereafter. Urine patches were the dominant sources for these emissions. On Day 9, a secondary emissions peak occurred, with dung pats likely to be the main sources. This interpretation is based on simultaneous observations of the pH evolution in urine patches and dung pats created next to the circular plot. Feed and dung samples were analysed to estimate the amounts of nitrogen (N) ingested and excreted. Total N volatilised as NH₃ was 19.8 (± 0.9)% of N intake and 22.4 (± 1.3)% of N excreted. The bimodal shape of the emissions time series allowed to infer separate estimates for volatilisation from urine and dung, respectively, with the result that urine accounted for 88.6 (± 2.6)% of the total NH₃ emissions. The emissions from urine represented 25.5 (± 2.0)% of the excreted urine-N, while the emissions from dung amounted to 11.6 (± 2.7)% of the deposited dung-N. Emissions from dung may have continued after Day 13 but were not resolved by the measurement technique. A simple resistance model shows that the magnitude of the emissions from dung is controlled by the resistance of the dung crust. © Author(s) 2013

    Optimizing monitorability of multi-cloud applications

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    When adopting a multi-cloud strategy, the selection of cloud providers where to deploy VMs is a crucial task for ensuring a good behaviour for the developed application. This selection is usually focused on the general information about performances and capabilities offered by the cloud providers. Less attention has been paid to the monitoring services although, for the application developer, is fundamental to understand how the application behaves while it is running. In this paper we propose an approach based on a multi-objective mixed integer linear optimization problem for supporting the selection of the cloud providers able to satisfy constraints on monitoring dimensions associated to VMs. The balance between the quality of data monitored and the cost for obtaining these data is considered, as well as the possibility for the cloud provider to enrich the set of monitored metrics through data analysis

    GAINE - tanGible Augmented INteraction for Edutainment

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    Interactive tabletops are gaining an increasing interest since they provide a more natural interaction with digital contents and allow the interaction of multiple users at a time promoting face-to-face collaboration, information sharing and the raise of social experiences. Given the potentialities offered by these devices, several entertainment-edutainment applications based on interactive tabletops have been successfully developed in different areas, from medical therapy support to children’s collaborative learning, interactive storytelling and cultural heritage. However, the development of such applications often requires complex technical and implementation skills. Taking this into consideration, in this paper we present GAINE (tanGible Augmented INteraction for Edutainment), a software framework aimed at the rapid prototyping and development of interactive tabletop games. GAINE offers developers context specific high-level constructs and a simple scripting language that simplifies the implementation task. The framework is portable on different operating systems and offers independence from the underlying hardware. Two practical case studies are thoroughly discussed to show how GAINE can simplify the development of interactive tabletop applications in the entertainment and edutainment contexts

    Decision-based fusion of pansharpened VHR satellite images using two-level rolling self-guidance filtering and edge information

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    Pan-sharpening (PS) fuses low-resolution multispectral (LR MS) images with high-resolution panchromatic (HR PAN) bands to produce HR MS data. Current PS methods either better maintain the spectral information of MS images, or better transfer the PAN spatial details to the MS bands. In this study, we propose a decision-based fusion method that integrates two basic pan-sharpened very-high-resolution (VHR) satellite imageries taking advantage of both images simultaneously. It uses two-level rolling self-guidance filtering (RSGF) and Canny edge detection. The method is tested on Worldview (WV)-2 and WV-4 VHR satellite images on the San Fransisco and New York areas, using four PS algorithms. Results indicate that the proposed method increased the overall spectral-spatial quality of the base pan-sharpened images by 7.2% and 9.8% for the San Fransisco and New York areas, respectively. Our method therefore effectively addresses decision-level fusion of different base pan-sharpened images

    Critical analysis of vendor lock-in and its impact on cloud computing migration: a business perspective

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    Vendor lock-in is a major barrier to the adoption of cloud computing, due to the lack of standardization. Current solutions and efforts tackling the vendor lock-in problem are predominantly technology-oriented. Limited studies exist to analyse and highlight the complexity of vendor lock-in problem in the cloud environment. Consequently, most customers are unaware of proprietary standards which inhibit interoperability and portability of applications when taking services from vendors. This paper provides a critical analysis of the vendor lock-in problem, from a business perspective. A survey based on qualitative and quantitative approaches conducted in this study has identified the main risk factors that give rise to lock-in situations. The analysis of our survey of 114 participants shows that, as computing resources migrate from on-premise to the cloud, the vendor lock-in problem is exacerbated. Furthermore, the findings exemplify the importance of interoperability, portability and standards in cloud computing. A number of strategies are proposed on how to avoid and mitigate lock-in risks when migrating to cloud computing. The strategies relate to contracts, selection of vendors that support standardised formats and protocols regarding standard data structures and APIs, developing awareness of commonalities and dependencies among cloud-based solutions. We strongly believe that the implementation of these strategies has a great potential to reduce the risks of vendor lock-in

    Genetic and phenotypic characterization of NKX6‐2‐related spastic ataxia and hypomyelination

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    Background and purpose Hypomyelinating leukodystrophies are a heterogeneous group of genetic disorders with a wide spectrum of phenotypes and a high rate of genetically unsolved cases. Bi‐allelic mutations in NKX6‐2 were recently linked to spastic ataxia 8 with hypomyelinating leukodystrophy. Methods Using a combination of homozygosity mapping, exome sequencing, and detailed clinical and neuroimaging assessment a series of new NKX6‐2 mutations in a multicentre setting is described. Then, all reported NKX6‐2 mutations and those identified in this study were combined and an in‐depth analysis of NKX6‐2‐related disease spectrum was provided. Results Eleven new cases from eight families of different ethnic backgrounds carrying compound heterozygous and homozygous pathogenic variants in NKX6‐2 were identified, evidencing a high NKX6‐2 mutation burden in the hypomyelinating leukodystrophy disease spectrum. Our data reveal a phenotype spectrum with neonatal onset, global psychomotor delay and worse prognosis at the severe end and a childhood onset with mainly motor phenotype at the milder end. The phenotypic and neuroimaging expression in NKX6‐2 is described and it is shown that phenotypes with epilepsy in the absence of overt hypomyelination and diffuse hypomyelination without seizures can occur. Conclusions NKX6‐2 mutations should be considered in patients with autosomal recessive, very early onset of nystagmus, cerebellar ataxia with hypotonia that rapidly progresses to spasticity, particularly when associated with neuroimaging signs of hypomyelination. Therefore, it is recommended that NXK6‐2 should be included in hypomyelinating leukodystrophy and spastic ataxia diagnostic panels

    Intraguild predation by Hippodamia variegata (Col.: Coccinellidae) on the parasitoid wasp, Lysiphlebus fabarum (Hym.: Braconidae)

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    Intraguild predation is defined as killing and eating another predator species as potential competitors that depends upon the same or limited resources. In this study, intraguild predation between the ladybird Hippodamia variegata Goeze and the parasitoid wasp Lysiphlebus fabarum (Marshall) was investigated in association with cotton aphid, Aphis gossypii, on cucumber plants. Host preference for healthy or previously parasitized aphids in third instar larvae and adult females of H. variegata was studied in a choice access situation as well as in a Y-tube olfactometer bioassay. We cut an antenna of each experimental aphid to reliably distinguish  the parasitized aphids from healthy ones. All experiments were performed at 22±1°C, 60%–70% RH, and a 16:8 (L:D) photoperiod. Based on the pre-test results, cutting the antenna of aphids, did not significantly affect the host preference of adults or third instar larvae of ladybirds. In a choice access test, female ladybirds significantly preferred healthy aphids to previously parasitized ones (24 and 72 hours: t =2.15, df =1,18, P =0.04 and t =6.35, df =1,18, P <0.001, respectively), but third instar larvae behaved differently  (t =0.58, df =1,18, P =0.56). According to olfactometer test results, female ladybirds preferred neither healthy aphids nor parasitized ones (χ2 =1.6, df =1,19, P =0.21). It is concluded that preference for healthy aphids over parasitized ones by adult female of H. variegata  facilitates the simultaneous application of the both biocontrol agents, H. variegata and L. fabarum

    Numerical investigation of turbulent CuO–water nanofluid inside heat exchanger enhanced with double V-cut twisted tapes

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    This numerical investigation aims to study the turbulent characteristics and thermal enhancement parameter of CuO–water nanofluids through heat exchangers enhanced with double V-cut twisted tapes. The twist ratio of the twisted tapes is 5.25, and the cut ratio (b/c) is varied from 0 (conventional twisted tape) to 1.8. The Reynolds number is in the range of 5000–15,000, and nanoparticles volume fraction is in the range of 0<ϕ<1.5%. The flow is fully turbulent, and (RNG) k − ϵ turbulent model is used for the numerical analysis. The results reveal that strong turbulent kinetic energy and additional vortex flow through the cuts of the modified twisted tapes are the main reason for better fluid mixing and heat transfer enhancement. The heat transfer enhances about 14.5% for the case of ϕ=1.5%. Furthermore, using double V-cut twisted tapes improves the Nusselt number of the nanofluid flow inside heat exchangers about 138% compared to conventional twisted tape without cuts. The maximum value of the thermal performance (η=1.99) is achieved by using nanofluid with ϕ=1.5% and b/c = 1.8 at Re = 5000
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